You need to keep in mind that the 1 3/4 tsp is for total intake and includes the sodium you consume that is already an instrinsic part of the other foods. So if you actually go through that much free salt you are getting way more sodium than you need.

On a fine note, while there is about 2300mg of sodium in a teaspoon of salt, there is a LOT more salt than that. Table salt is only 39% sodium (by weight) and so a tsp of salt weighs about 5800 mg.